How is "responsibility" formally defined, and what four questions decompose it?

Question

Accepted Answer

Responsibility is "a subject standing up for an object" — analysable by asking who, for what, how, and before whom.
The formal definition is deliberately abstract: the standing-up (Eintreten) of a subject for an object. That bare frame is useful because any concrete case of responsibility can be unpacked with four questions:

WHO — who is/are the bearer(s) of the responsibility? (the subject)
FOR WHAT — what is the object the responsibility is about? (the object)
HOW — in what way is the responsibility exercised? (the relation)
BEFORE WHOM — who is the authority that the bearer answers to? (the instance)

The connection to critical thinking: the thesis is that critical thinkers build habits of thought and character that have a deeper, more holistic effect on their own development and, indirectly, on others. Taking responsibility for how you reason and what you pass on is part of that.
Tip: Subject — Object — Relation — Instance. Plug a real example into all four (e.g. an engineer / for a bridge's safety / by inspecting it / before the public and the law) and the abstract definition turns concrete.